METHOD TO CALL INFLOW OF FORMATION FLUID FROM WELL Russian patent published in 2012 - IPC E21B43/25 E21B43/18 E21B47/06 

FIELD: oil and gas production.

SUBSTANCE: method to call inflow of a formation fluid from a well includes lowering of a tubing string into a well, reduction of pressure to a payout bed of liquid displacement column into a well with a gas-liquid mixture by means of its supply into an annular space with a booster device, provision of the required ratio of mixture components to achieve the specified value of pressure reduction at the payout bed. Prior to lowering into the well, a remote depth pressure gauge is installed on the lower end of the tubing string. Replacement of the entire liquid column in the well is carried out with pumping of a gas-liquid mixture (foam), including a surfactant, into the annular space with a booster device, at a low extent of aeration - 10-20 m³/m³. After appearance of foam circulation the extent of aeration is gradually increased to 150-160 m³/m³, and the average density of foam is brought to 100-120 kg/m³. Foam circulation is continued to achieve the specified value of reduced pressure at the payout bed, which is determined by readings of the remote depth pressure gauge. Afterwards foam circulation is stopped for 2-3 hours. The possible inflow of the formation fluid is determined from the well. If there is no inflow of the formation fluid, foam circulation is stopped, an annular valve is closed, and foam is pushed along the tubing string into the bed in the amount of 5-10 m³ with soaking in the bed for 3-4 hours. Afterwards the annular valve is opened, and foam circulation is restored at maximum extents of aeration to produce inflow of the formation fluid from the well.

EFFECT: increased quality and efficiency of calling for inflow of a formation fluid.

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